1. Math 4-2: Warm-up

2. Objective: How to find rates of change.
Math 4-2: Rate of Change
Objective: How to find rates of change.

3. Vocabulary
rate of change – a rate that describes how one quantity changes in relation to another. (always expressed as unit rate)

4. Rate of Change always read graphs from left to right
divide the difference in the y-coordinates by the difference in the x-coordinates (unit rate)
x-axis – denominator – ALWAYS time

5. Find a Rate of Change
The table below shows the weight of a dog in pounds between 4 and 12 months old.
Age (mo.) 4 8 12
Weight (lb.) 15 28 43
Find the rate of change in the dog’s weight between 8 and 12 months of age.

7. Find a Rate of Change
The graph shows Mr. Smith’s annual income between 1994 and Find the rate of change in Mr. Smith’s income between 1996 and 2002.
Annual Income ($1000) y
’ ’ ’ ’ ’ x
Year

9. Rates of Change Rate of Change Positive Zero Negative Meaning Increase
No Change
Decrease
Graph

10. Study Guide & Intervention
The graph shows the number of 8th grade students between 1998 and Find the rate of change between 2000 and 2002.
Number of students y
’ ’ ’ ’ ’ x
Year

11. Assignment
4-2 PS (a)
Quiz: Lessons 1-3 – 10/20